Electrical condenser for liquid volume indicators



Oct. 14, 1947. H. WAYMOUTH 2,428,898

ELECTRICAL CONDENSER FOR LIQUID VOLUME INDICATQRS Filed Dec. 30, 1944 3 Sheets-Sheet 1 Maw Oct. 14, 1947. H. WAYMOUTH ELECTRICAL CONDENSER FOR LIQUID VOLUME INDICATORS 3 Sheets-Sheet 2 Filed Dec. 30, 1944 37 Oct. 14, 1947. H. WAYMOUTH ELECTRICAL CONDENSER FOH LIQUID VOLUME INDICATORS Filed Dec. :50; 1944 I 3 Sheets-Sheet I5 lllalu lll llll ll'lllll I.

l I: I

Invent Patented Oct. 14, 1947 ELECTRICAL CONDENSER. FOB LIQUID VOLUME INDICATORS Henry Waymouth, Harrow,

Waymouth Gauges and England, assignor to Instruments Limited,

Harrow, Middlescx, England Application December 30, 1944, Serial No. 570,693 In GreatBritain December 30, 1943 '16 Claims.

This invention relates to electrical condensers forliquid volume indicators and more particularly to liquid fuel tank condensers for electrical fuel contents gauges.

Electrical fuel contents gauges for indicating the volume of liquid fuel in fuel tanks, more especially for aircraft, have previously been pro posed. For example, our patent specification No. 513,771 relates to the ume indicator in which the gauge reading varies known type of liquid volwith the capacity of a condenser within the tank,

the capacity of the condenser in turn depending upon the extent to which the condenser is immersed by the liquid in the tank.

It is an object of the present invention to provide an improved electrical condenser for a liquid voluine indicator which is especially adapted for use in a flexible fuel tank suchas the rubber or like tanks which are now in use in aircraft.

It is a furtherobject of the invention to provide a fuel tank condenser for an electrical, fuel contents gauge, which condenser can be inserted the-plates 20, 2i'

a i 2 Figure 9 is a complete small scale elevation of the condenser,

Referring to the drawings the plates of the condenser consist of two series 20, 2|, of substantially rigid metal plates or strips preferably of a light metal or alloy-such as aluminium or'duralumin. The plates outer plates of twelveelement'al condensers de- 20 of one series constitute the noted respectively by the numerals i'--i2 and the plates 2i of the otherfse'ries constitute theinner plates of these plates 20, 2| being channel-shaped for strengthening purposes; The condensers i- -IZ formed by are secured at intervalsalong their length on lengths of flexible belting such as 22, adapted-t0 be secured'at their e'ndsitothe self sealing petrol tank 23 comprising layers of rubher and rubberisedfabric such as, an inner synthetic rubber and canvas compositepetrol tight layer 40, which provides the 'main strength of the tank, an intermediate rubber self-sealing layer and mounted in a substantially closed flexible tank to form therein a partition of substantially the same shape and size as the cross sectional area of the tank.

A further object of the invention is to provide an improved device for quickly assembling the plates of anelectrical condenser in proper spaced relationship.

The foregoing andother objects of the invention will be made clearer with the aid of the following description relating to the accompanying drawings, in which:

Figure 1 is an interrupted vertical section through a self-sealing petrol tank such as'is used in aircraft fitted with a liquid volume indicator comprising an electrical condenser made according to the invention;

Figure 2 is a part side view of Figure 1;

Figure 3 is an enlarged sectional view of the upper part of Figure 1 illustrating the manner in which the condenser is secured at one end, and the connection of the condenser to an outside terminal;

Figure 4 is a perspective detail view illustrating the assembly of the condenser plates;

Figures 5 and 6 are respectively detail views illustrating a spacing'member and the means for securing-it to a condenser plate} Figure '7 is a, diagram illustrating the electrical connections of the condenser plates;

Figure 8 illustrates the condenser in a collapsed or folded condition ready for insertion in one of the hand holes of an aircraft petrol tank; and

42 which when wetted by the .petrol expands and fills any small holes, and an outer protecting rub ber layer 4i. Theineans for securing thepcondensers l--i2 to the belt comprise shallow metal trough-shaped fixing plates 24 riveted tothe belt '22 and havinghorizontal flanges 25 by means-of which they canbe riveted'or otherwise secured to the inner condenser plates 2|. The outer plates 20 are'connec'ted to the inner plates by meansoi' spacing members such as shown in Figure 5."v As shown in this figure the spacing memb'er ZG is v cruciform having two opposite arms apertured as at 2|. These apertured arms project'respectively through slots provided therefor in the plates 20, 2i and are secured by means of flanged U-shaped clips 28 having apertures 28 coinciding with the apertures 21 whereby they can be secured in position by eyelets or other suitable means. The cruciform members 20 can suitably be stampings of sheet synthetic resinpdnveniently reinforced with linen or other textile material. The clips 28 mayconveniently be made of springy brass, the flanges thereon acting in the manner of leaf springs to hold the plates firmly against the central portion of the member 26, thereby preventing rattling of the parts and at the same time permitting expansion and contraction to' take place freely.

The spacing members 26 are preferably arranged, as shown in Figure 4, so that their planes extend alternately in diiierentdirections, preferably at' right angles, in order to increase the stability of the structure.

To each side of the belt is secured a strip 29 elemental condensers, all the of light gauge metal braid against which the 11xing plates 24 are pressed in such a manner as to provide good electrical contact, thereby ensuring that all the inner plates 2| are electrically connected to the braid 29. The outer plates2l are also electrically connected together by strips 30 of light gauge braid enclosed in an insulating sleeving and connected to the outer plates by plates 43 screwed or riveted to the outer plates 20.

Each belt 22 is secured at the bottom to a. flxing bracket 3! of inverted T-shape which in turn is secured to the inner layer 40 of the tank. At the top each belt 22 is fastened to an L-shaped fixing bracket 32 secured to the wall of the tank by bolt 32', one such bracket having an aperture to receive the waist 33 of an insulating bush comprising an inner part 34 and an outer part 35. A bolt 36 is screwed into the bush 34, 35 and is electrically connected at its inner end to the braid 30 and at its outer end constitutes a terminal 31' for a lead-in conductor 31. The terminal 31' is enclosed in a terminal box 38, which is bolted to the bracket 32 by the bolt 32' and provided with a second terminal 38'.

Electrical connection between the terminal 38 and the inner plates 2! of the condensers is provided by the terminal box 38, bolts 32, plate 32 and bolts 44, 45 (Fig. 3) constituting conductors between the inner plate 2| of the top elemental condenser (in electrical contact with the conducting strip 29) and the plate 32.

Suitable electric leads are provided for connecting the terminals and each series of plates associated therewith to the electrical circuit of the indicator outside the tank.

It will be evident from the foregoing and from the diagram of Figure 7 that the elemental condensers l-IZ are connected in parallel.

The staggered relationship of the elemental condensers ii2 on opposite sides of the belt 22 permits the arrangement to be folded up or collapsed into small compass'as shown in Figure 8 so that it can be passed into the interior of the petrol tank through one of the hand holes usually provided and denoted by 39 in Figure 8. After insertion it is opened out and secured in the manner described, the handholes being subsequently closed, for example by rubber discs clamped between metal plates.

It is to be understood that the invention is not limited to the particular construction described. For example, the shape of the plates 20, 2| may be varied to suit the cross-sectional shape of the tank and one or more condensers may be used in a single tank.

What I claim is:

1. An electrical condenser comprising a flexible support, a. plurality of elemental condensers mounted on said support, and means for electrically connecting said condensers in parallel, wherein the plates of each elemental condenser are spaced apart by cruciform spacing members of insulating material, opposite arms of which project through slots in the plates and are secured therein by clips arranged for connection to said projecting arms.

2. An electrical condenser according to claim 1, wherein the spacing members are stamped from a sheet of insulating material.

3. An electrical condenser according to claim 1, wherein the projecting arms of the spacing members, and the securing clips, are aperturedto receive eyelets, and the clips are made of springy material and have flanges bearing on the plates.

clips are of U-shape and embrace the projecting arms, and the securing means comprise apertures provided in the extending arms, in line with similar apertures provided in the walls or the clips,

- to receive eyelets or like securing means.

8. Means according to claim 6, wherein the spacing members are stamped from sheet insulating material.

9. Means according to claim 6, wherein the clips are made of springy metal and are formed with flanges bearing against the condenser plate for the purpose specifled.

10. An electrical condenser for a liquid volume indicator comprising a flexible support, a plurality of elemental condensers mounted on opposite sides of said support, the condensers on one side being out of alignment with the condensers on the other side, each of said condensers comprising two plates in spaced relationship, and means for electrically connecting all said condensers in parallel.

11. An electrical condenser for a liquid volume indicator, comprising a flexible support, a plurality of elemental condensers mounted on opposite sides of said support, the condensers on one sidebeing out of alignment with the condensers on the other side, each of said condensers comprising two plates in spaced relationship, means for electrically connecting all said condensers in parallel, and means associated with said flexible support for fixing said support inside the wall of a vessel.

12. An electrical condenser for a liquid volume indicator comprising a flexible support, a plurality of elemental condensers mounted on said support, means for electrically connecting said condensers in parallel, and means associated with the ends of said flexible support for flxing to, and extending said support between, the inner surfaces of the top and bottom 01 a vessel.

'13. An electrical condenser for a liquid volume indicator comprising a flexible support, a plurality of elemental condensers mounted on at least one side of and along the length of said support, each of said condensers comprising two plates in spaced relationship, and means for electrically connecting said condensers in parallel, the arrangement being such that the composite condenser can be folded into a relatively small compass when not in use, and unfolded to space the said elemental condensers when set up for use.

14. An electrical condenser according to claim 13 comprising a plurality of elemental condensers mounted on opposite sides of said flexible support.

15. An electrical condenser according to claim 11 wherein said elemental condensers are secured to said flexible support by means of rigid metal flxing plates.

16. A vessel fltted internally with an electrical condenser according to claim 11, wherein one series of like plates of the condenser are elec- 5 trically connected through fixing plates to flexible conducting strips secured on both sides of said flexible support, said strips being electrically connected to a, terminal on the wall of the vessel,

and the other series of like plates are electrically connected to a second terminal by a flexible conducting member or members.

HENRY WAYMOU'I'H.

REFERENCES CITED The following references are of record in the file oi this patent: 

